Tony Abbott says he was headbutted by a same-sex marriage campaigner in Hobart

Former prime minister Tony Abbott says he was headbutted by a same-sex marriage campaigner in Hobart, leaving him with a “very slightly swollen lip”.

The campaigner, who Abbot said was wearing a “Vote Yes” badge, reportedly asked to shake Abbott’s hand when he attacked him.

“He wasn’t very good at it, I’ve got to say, but he did make contact. The only damage was a very, very slightly swollen lip,” Abbott told the ABC.

“I was with a member of my staff, [who] briefly grappled with this guy and then he ran off swearing his head off, basically.”

He said it was “a reminder of how ugly this debate is getting”.

“And the ugliness is not coming from the defenders of marriage as it’s always been understood — the ugliness, the intolerance and indeed in this instance, the hint of violence, is coming from those who tell us in the name of decency and fairmindedness and freedom, we’ve got to allow same-sex marriage.”

He added: “If the actual debate about same-sex marriage is producing this kind of intolerance and bullying, how much worse would it get if the brave new world of same-sex marriage actually came to be?”

Abbott, a long-time anti-marriage equality advocate, was in Tasmania to attend a Young Liberal cocktail party.

Tasmania Police are investigating the alleged assault “involving a 59-year-old man from New South Wales” and have appealed for witnesses to the incident to come forward.

The incident was widely condemned by both sides of the same-sex marriage debate, with politicians and campaigners from both sides of the fence against violence.

Earlier this month, former prime minister Kevin Rudd’s godson was also attacked for defending the “Yes” vote on same-sex marriage.

The 19-year-old was allegedly assaulted after attempting to stop a man removing banners in Brisbane supporting marriage equality.

In an Instagram post, Rudd said: “So many warnings to Turnbull about what this postal vote could unleash. Now my godson Sean has been punched while sitting at his bus stop, for objecting when a man began ripping down rainbow banners and hurling verbal abuse.”